Microsoft (NASDAQ: MSFT) is roughly a week away from unveiling the next version of Surface.

Surface 2 (the presumed name of the upgrade) is expected to come in multiple sizes, including a seven-inch model designed to compete with Apple's (NASDAQ: AAPL) iPad Mini and Google's (NASDAQ: GOOG) Nexus 7. It is not yet known if there will be a third size to accompany the launch, but Apple and Samsung (OTC: SSNLF) are both rumored to be developing new 12-inch tablets.

If a seven-inch model is added to the mix, Microsoft could release as many as three or four new tablets (10-inch versions of Surface RT and Surface Pro, and a seven-inch version of RT and/or Pro). This would make it Microsoft's biggest product launch yet.

Unlike most tablet manufacturers, Microsoft chose not to rely on third-party developers to deliver a keyboard attachment.

When the first Surface arrived, there were two keyboard choices from Microsoft. One of them offered a soft, pressure-sensitive feel, while the other was a full tactile keyboard with real keys. Both also served as a cover for the tablet.

For Surface 2, Microsoft is expected to add a third cover to the mix, one that provides extra battery life to the device.

This unit is currently being referred to as a "Power Cover," but that may not be the name Microsoft uses if and when the company ships the cover to retail.

The dock is rumored to include a mini DisplayPort for video out, one USB 3.0 port, three USB 2.0 ports and a single 1 Gbps Ethernet port. The doc will also contain dedicated ports for a headphones or a microphone.

Oddly, the docking station is not expected to be compatible with any version of Surface RT -- not even the new iteration due this fall.

Disclosure: At the time of this writing, Louis Bedigian had no position in the equities mentioned in this report.

Louis Bedigian is the Senior Tech Analyst and Features Writer of Benzinga. You can reach him at 248-636-1322 or louis(at)benzingapro(dot)com. Follow him @LouisBedigianBZ